form wrote in post #11923640
Crop cameras have benefits of extra "effective" reach, greater "effective" DoF, and higher "effective" magnification for minimum focus distance. These are all useful in the right hands.
No crop camera can use a 24mm f/1.4 lens and get the same wide perspective with the same narrow DoF and low light capabilities as a full frame camera because there are no f/1.4 lenses that are effectively 24mm when adding the crop factor. No crop camera can get the same framing and have exactly the same image at the same aperture setting as a full frame camera.
That's true, but from a photographer's perspective, it's not the aperture that matters, it's the depth of field. And that's probably what you really meant here.
For a given framing, a crop camera will simply not be able to match a full frame camera's ability to generate a shallow depth of field. If you need a depth of field that shallow, nothing other than a full frame camera will do.
But that's only if you really need such a shallow depth of field. The types of shots where you'd need that and couldn't get it with a crop camera appear to be limited primarily to ultra wide angle shots, where the primes that make that possible exist for full frame cameras and not for crop cameras.
For everything else, it's a question of the selected lens, and that's obviously going to be different for the full frame camera than for the crop camera.
Full frame will get you more flexibility than crop, so if all else were equal, full frame would be the way to go for sure. But Canon has ensured that not all else is equal (particularly with respect to autofocus).
That doesn't really address the original question, which is whether or not a crop camera is suitable for shooting a wedding. It most surely is, as you yourself know because you were quite successfully shooting weddings with a crop camera for some time before you got a full frame body. You can argue, perhaps, that it wasn't sufficient for you and that's what motivated you to go full frame, but I'd bet dollars to doughnuts that your clients were ecstatic with your work when you were shooting with just a 40D. I saw some of the work you did back then and no client in their right mind would be anything but overjoyed with it.